Lingering house smells are frustrating, especially when you work so hard to keep your house clean. They can also be concerning for your health and safety when it comes to harmful airborne particles infiltrating the air. When you can’t specifically see grime or sweaty gym socks causing a bad odor, it might take some deeper investigation — there are plenty of hidden causes of odor throughout your home. Here are eight bad smells, the common causes, and how to solve them. 

1. Musty, “Old Home” Smell 

The Common Cause

The smell of mold or mildew growing in your home is usually described as a musty, “old home” smell. It likes to grow in humid, dark places like bathrooms, laundry rooms, or basements. You can sometimes actually see the mold growing on the walls, in crevices, or along window sills and frames, but oftentimes it’s hidden inside the walls or under the carpet. 

Is It Harmful? 

It depends on the situation. In some cases, such as a small amount of mold growing on a windowsill, it’s fairly non-toxic, but it should still be removed before it can spread. Other mold situations are more serious, especially if you can smell it without being able to see it. Toxic mold can cause allergies, asthma, and severe respiratory problems for people who are sensitive to it. 

How to Solve It 

There are a number of DIY methods that homeowners try to remove mold from within their home. The most common ones that we see involve a mixture of bleach and water. While this might serve as a temporary solution, your best bet is to hire a professional mold removal company that will probably remove it so it doesn’t continue to grow back.

Once the mold is removed, you can prevent it from coming back by taking the following steps: 

  • Regulate the moisture in the air with a dehumidifier
  • Improve the ventilation in moisture-prone rooms such as bathrooms or laundry rooms 
  • Fix any leaky fixtures or cracked pipes 
  • Take extra care while cleaning high-moisture rooms 

2. Sulfur or Rotten Eggs Smell

The Common Cause

If your home uses natural gas for heating and you smell sulfur or rotten eggs, it might be a gas leak. Natural gas is naturally odorless, but gas companies add the “rotten egg” smell as a precaution to keep homeowners safe. Some additional signs include: 

  • A hissing sound near a gas line
  • A damaged gas pipe
  • Bubbles forming in water
  • Dead houseplants

Is It Harmful? 

Yes, gas leaks are serious. If you smell rotten eggs, you should leave your house immediately. A gas leak could cause symptoms such as fatigue, headaches, or chest pain, and could potentially be fatal. It’s also flammable, so an open flame could cause a fire or explosion. 

How to Solve It 

Call your gas company immediately, and they will take care of the situation. Do not do anything that could cause a spark, such as turning on the lights or an appliance, starting your car (if it is in an attached garage), or lighting a candle. 

3. Smoke or Other Lingering Smells 

The Common Cause

Smells that have absorbed into your carpet or walls over time might not be obvious to you, but it could be the first thing someone notices when they enter your home. There are a number of smells that can live in your carpet or walls, including spilled food or drinks, pet urine, and smoke. If any of those situations apply to you, even if the carpet and walls appear clean, you might need to consider going the extra mile to remove the smell. 

Is It Harmful? 

While it’s not initially harmful, the causes of these lingering smells could affect you over time. Spilling a beverage or pet urine that isn’t properly treated the first time could cause allergy-like symptoms or mold growth after a while. Along with that, smoke particles that have clung to the wall or carpet is known as “thirdhand smoke.” While some suggest thirdhand smoke can play a part in causing cancer, the specific effects still aren’t clear.

How to Solve It 

For your walls, you can start by doing a deep clean of the walls, ceilings, and baseboards. There are a couple of different solutions you could use, including:

  • A 1:1 warm water and white vinegar spray 
  • An ammonia solution, composed of ½ cup of ammonia for each gallon of warm water 

If you’ve deep cleaned the walls and the odor is still there, the easiest way to get rid of it is by applying a fresh coat of paint. 

As for your carpets, if the stain is already removed, try sprinkling baking soda on them and let it sit overnight, then vacuum in the morning. If that doesn’t work, try renting a steam cleaner or other carpet cleaner with a cleaning solution. If all else fails, reach out to a cleaning professional to expertly get rid of the odor. 

4. The Smell of Rotten Food

The Common Cause

It’s counterintuitive to think that something made to clean and sanitize your dishes needs cleaning itself, but scraps of food could get stuck in weird parts of your dishwasher. If you smell old food in your kitchen, especially around your dishwasher, it’s probably time for a deep clean. 

Is It Harmful?  

Trapped, old food isn’t harmful, just gross. However, mold can hide in parts of your dishwasher as it’s a moist place, but any mold found there should be relatively harmless and easy to clean. 

How to Solve It 

You should regularly clean your dishwasher, about once a month, by running it with a cup of vinegar or by sprinkling baking soda across the bottom when you run it. If you notice a gross smell, you should perform a deep clean. Use a vinegar and water solution to clean, focusing on two key areas: the seals and the dishwasher trap. Also, don’t forget to wipe down the rubber seal around the dishwasher door, and remove any buildup around the area. 

5. Pungent, Sickly Smell

The Common Cause

If there’s a dead animal decomposing somewhere in your home, the sickly smell is hard to miss. You’ll be able to pinpoint the location or area of your home where it’s hiding — some typical areas include the wall, the attic, the chimney, or under the house. 

Is It Harmful? 

Worse than the putrid smell, it’s important to remove the animal to avoid any potential health issues. Decomposing animals can release bacteria that cause health complications, and animals such as rats can carry disease.

How to Solve It 

If you’re able to identify the source, you can remove the animal yourself by following your city’s sanitation guidelines. If you don’t want to deal with it or cannot access the carcass, call a pest control company. Once it’s removed, make sure to patch up any holes or access points that allowed the animal to enter in the first place to prevent any future issues. 

6. Fishy Smell 

The Common Cause

If you haven’t prepared fish recently and you’re perplexed by a fishy smell in your house, it could be an electrical problem. This smell is the first sign of an overheated or burning electrical component. You can try and look for the source, such as a melting outlet or frayed wires, but you’ll need a pro to determine if it’s something such as an incorrectly sized breaker or burning wires inside the wall or ceiling. 

Is It Harmful? 

Yes, faulty wiring or overheated electrical components are dangerous and could even start a house fire. 

How to Solve It 

First, make sure the smell isn’t caused by a piece of plastic or other material that’s too close to a heat source. If you can’t find the source of the smell, you need to call an electrician as soon as possible. They will be able to determine the cause of the smell by using infrared cameras to pinpoint the source and repair it as needed. 

7. Old Gym Bag Smell  

The Common Cause

Bacteria buildup on heating system coils is usually described as the “Dirty Sock Syndrome.” If it smells like an old gym bag throughout your home with no dirty clothes in sight, it could be your coils. This is especially likely during the spring and fall when your system is cycling between the heat and AC. 

Is It Harmful?

If you or someone in your home is sensitive to allergens, then “Dirty Sock Syndrome” could cause issues as any other bacteria would, but it’s not outright harmful. Any growth, though, should be taken care of before it gets out of hand or affects the indoor air quality. 

How to Solve It 

You can get rid of this stench by cleaning your evaporator coils with a non-acid coil cleaner. If you’re hesitant about cleaning them yourself or are looking for a professional opinion, get in touch with an HVAC professional. 

8. Sewage or Rotten Eggs Smell

The Common Cause

If it smells like sewage and rotten eggs in your bathroom, it’s probably sewage gas — the odor is pretty hard to miss. It’s especially likely to happen with drains that aren’t regularly used. 

Is It Harmful? 

Small amounts of sewer gas aren’t harmful, but chronic exposure or high levels of sewage gas can be toxic. If you and your family are chronically exposed to the compounds in sewage gas, it could cause symptoms such as fatigue, nausea, and headaches. 

How to Solve It 

A short-term solution would be flushing the toilet and running your sink and bathtub to eliminate the smell. This can temporarily suppress the smell, but there’s typically an underlying cause for the sewage gas, such as cracked pipes or clogged drains. If there’s a recurring sewage smell, you should consult a plumber. 

Contact ServiceMaster by Rice to Eliminate Odors 

If you’re struggling to find the cause of an odor or want a professional to find and eliminate it, contact the pros at ServiceMaster by Rice. Our expert team will find the source of the odor, then determine the best strategy to eliminate it and get your home back to odor-free, clean air. Our trusted team, specialty equipment, and green-friendly products will get you breathing easy in no time. We also specialize in services that deal with the underlying cause of many home odors, such as mold removal, water and flood damage, carpet cleaning, and more.